The present invention relates to a control apparatus and control method that control the operation of a moving member, such as the roof glass, window glass or slide door of a vehicle, which opens or closes the opening.
In an ordinary sunroof apparatus equipped on a vehicle, a roof glass which is actuated by a drive motor opens or closes an opening provided in the roof of the vehicle. This sunroof apparatus has capabilities of detecting a foreign matter being caught between the roof glass and the periphery of the opening during the closing actuation of the roof glass and reversing the moving direction of the roof glass to an opening direction from a closing direction when a foreign matter is caught there during the closing actuation of the roof glass. Specifically, a control circuit which controls the drive motor detects the rotational speed of the drive motor, and when the detected rotational speed becomes lower than a predetermined decision value, the control circuit determines that a load is applied to the drive motor due to the caught foreign matter and reverses the rotational direction of the drive motor to reverse the moving direction of the roof glass.
When the supply voltage to be supplied to the control circuit drops, the relay that drives the drive motor may not be operated due to the insufficient voltage, thereby stopping the operation of the drive motor. The threshold value of the voltage that makes such a relay inoperable varies from one relay to another. The control circuit stops the drive motor in operation or inhibits the operation of the drive motor when the supply voltage becomes lower than a predetermined reference voltage, so that the voltage value at which the drive motor becomes inoperable due to such a variation in threshold value does not vary from one sunroof apparatus to another.
The supply voltage may also drop during the operation of the drive motor. When a load is applied to the drive motor due to a foreign matter caught in the roof glass, particularly, the current to the motor increases, thus causing a relatively large drop in supply voltage.
In a case where a foreign matter having a low rigidity is caught in the roof glass, the voltage drop becomes greater. In other words, the time during which the voltage is being dropped becomes longer. Therefore, the control circuit detects a voltage abnormality as a result of the supply voltage becoming less than the reference voltage and stops the drive motor before detecting a foreign matter being caught in the roof glass based on a reduction in the rotational speed of the drive motor. As a result, the moving direction of the roof glass is not reversed to the opening direction so that the roof glass is stopped moving with a foreign matter caught in the roof glass.
Accordingly, it is an objective of the present invention to provide a control apparatus and control method for a moving member, which can reliably detect a foreign matter being caught in the moving member and can release the foreign matter.
To achieve the object, the present invention provides an apparatus that controls a moving member movable between an opening position in which an opening of a frame is opened and a closing position in which the opening of the frame is closed. The apparatus comprises a drive motor, a switch and a control section. The drive motor actuates the moving member when applied with a drive voltage. The switch is operated to actuate the moving member. The control section controls the supply of the drive voltage to the drive motor in accordance with an operation of the switch. The control section rotates the drive motor reversely to reverse the moving direction of the moving member when movement of the moving member is obstructed by a caught foreign matter while the moving member is moving toward the closing position. The control section determines that the drive voltage is abnormal based on the drive voltage becoming lower than a predetermined reference voltage. The control section inhibits the drive motor from being operated when having determined an abnormality of the drive voltage and stops supplying the drive voltage to the drive motor. The control section sets the reference voltage to a selected one of a first value and a second value lower than the first value and sets the reference voltage to the second value at least while the moving member is moving toward the closing position.
The present invention also provides a method that controls a moving member movable between an opening position in which an opening of a frame is opened and a closing position in which the opening of the frame is closed. The method comprises a step of causing the drive motor to actuate the moving member by applying a drive voltage to the drive motor, a step of rotating the drive motor reversely to reverse the moving direction of the moving member when movement of the moving member is obstructed by a caught foreign matter while the moving member is moving toward the closing position, a step of determining that the drive voltage is abnormal based on the drive voltage becoming lower than a predetermined reference voltage, a step of stopping supplying the drive voltage to the drive motor to inhibit the drive motor from being operated when an abnormality of the drive voltage has been determined, and a step of setting the reference voltage to a selected one of a first value and a second value lower than the first value. The reference voltage is set to the second value at least while the moving member is moving toward the closing position.